U.S. patent application number 12/750834 was filed with the patent office on 2011-10-06 for methods and apparatus for determining a communications mode and/or using a determined communications mode.
This patent application is currently assigned to QUALCOMM Incorporated. Invention is credited to Junyi Li, Vincent D. Park.
Application Number | 20110244899 12/750834 |
Document ID | / |
Family ID | 44120937 |
Filed Date | 2011-10-06 |
United States Patent
Application |
20110244899 |
Kind Code |
A1 |
Li; Junyi ; et al. |
October 6, 2011 |
METHODS AND APPARATUS FOR DETERMINING A COMMUNICATIONS MODE AND/OR
USING A DETERMINED COMMUNICATIONS MODE
Abstract
Methods and apparatus for determining a mode of wireless
communications to be used by a wireless terminal, e.g., a direct
communications mode or an infrastructure communications mode are
described. In some embodiments, the mode to be used is determined
by a control node based on interference which will be caused to the
system taking into consideration at least an area, e.g., cell, in
which the wireless terminal seeking to communicate is not located.
System interference cost estimates for each mode under
consideration are generated and compared. Interference cost
estimates may, and do, correspond to different frequency bands when
the direct mode uses a different frequency band than the
infrastructure communications mode. Separate interference cost
estimates and mode determinations are made for different
communications directions in some embodiments. The determined mode
to be used is communicated to the devices seeking to communicate,
e.g., via one or more base stations.
Inventors: |
Li; Junyi; (Chester, NJ)
; Park; Vincent D.; (Budd Lake, NJ) |
Assignee: |
QUALCOMM Incorporated
San Diego
CA
|
Family ID: |
44120937 |
Appl. No.: |
12/750834 |
Filed: |
March 31, 2010 |
Current U.S.
Class: |
455/501 |
Current CPC
Class: |
H04W 76/14 20180201;
H04W 88/06 20130101 |
Class at
Publication: |
455/501 |
International
Class: |
H04B 15/00 20060101
H04B015/00 |
Claims
1. A method of operating a control device, the method comprising:
determining a first mode of operation for communication from a
first wireless terminal, located in a first base station coverage
area, to a second wireless terminal as a function of interference
which will be caused in a second base station coverage area
adjacent said first base station coverage area, said first mode of
operation being one of a direct mode of operation and an
infrastructure mode of operation; and communicating to the first
wireless terminal the determined first mode of operation to be used
for communication from the first wireless terminal to the second
wireless terminal.
2. The method of claim 1, further comprising: determining a second
mode of operation for communication from the second wireless
terminal to the first wireless terminal as a function of
interference which will be caused in a base station coverage area
other than a base station coverage area in which said second
wireless terminal is located, said second mode of operation being
one of said direct mode of operation and said infrastructure mode
of operation; and communicating to the second wireless terminal the
determined second mode of operation to be used for communication
from the second wireless terminal to the first wireless
terminal.
3. The method of claim 1, wherein said second wireless terminal is
located in the second base station coverage area.
4. The method of claim 1, wherein said first and second wireless
terminals are located in the first base station coverage area.
5. The method of claim 2, wherein communicating to the first
wireless terminal the determined first mode of operation includes
transmitting the determined first mode of operation to the first
wireless terminal via a first base station included in the first
base station coverage area.
6. The method of claim 1, wherein determining said first mode of
operation is also a function of interference which will be caused
in a base station coverage area other than a base station coverage
area in which said second wireless terminal is located, if the
determined first mode is used for communication from said second
wireless terminal to the first wireless terminal.
7. A communications device comprising: at least one processor
configured to: determine a first mode of operation for
communication from a first wireless terminal, located in a first
base station coverage area, to a second wireless terminal as a
function of interference which will be caused in a second base
station coverage area adjacent said first base station coverage
area, said first mode of operation being one of a direct mode of
operation and an infrastructure mode of operation; and communicate
to the first wireless terminal the determined first mode of
operation to be used for communication from the first wireless
terminal to the second wireless terminal; and a memory coupled to
the at least one processor.
8. The communications device of claim 7, wherein the at least one
processor is further configured to: receive interference
information from a second base station, said interference
information including at least one of: i) interference information
determined by said second base station from a signal received by
said second base station from the first wireless terminal and ii)
interference information determined by a third wireless terminal in
the second base station coverage area which was reported to said
second base station.
9. The communications device of claim 7, wherein the at least one
processor is further configured to: determine a second mode of
operation for communication from the second wireless terminal to
the first wireless terminal as a function of interference which
will be caused in a base station coverage area other than a base
station coverage area in which said second wireless terminal is
located, said second mode of operation being one of said direct
mode of operation and said infrastructure mode of operation; and
communicate to the second wireless terminal the determined second
mode of operation to be used for communication from the second
wireless terminal to the first wireless terminal.
10. The communications device of claim 7, wherein said second
wireless terminal is located in the second base station coverage
area.
11. The communications device of claim 9, wherein in communicating
to the first wireless terminal the determined first mode of
operation, the at least one processor is further configured to
transmit, the determined first mode of operation to the first
wireless terminal via a first base station included in the first
base station coverage area.
12. The communications device of claim 7, wherein determining said
first mode of operation is also a function of interference which
will be caused in a base station coverage area other than a base
station coverage area in which said second wireless terminal is
located, if the determined first mode is used for communication
from said second wireless terminal to the first wireless
terminal.
13. A communications device comprising: means for determining a
first mode of operation for communication from a first wireless
terminal, located in a first base station coverage area, to a
second wireless terminal as a function of interference which will
be caused in a second base station coverage area adjacent said
first base station coverage area, said first mode of operation
being one of a direct mode of operation and an infrastructure mode
of operation; and means for communicating to the first wireless
terminal the determined first mode of operation to be used for
communication from the first wireless terminal to the second
wireless terminal
14. The communications device of claim 13, further comprising:
means for receiving interference information from a second base
station, said interference information including at least one of:
i) interference information determined by said second base station
from a signal received by said second base station from the first
wireless terminal and ii) interference information determined by a
third wireless terminal in the second base station coverage area
which was reported to said second base station.
15. The communications device of claim 13, further comprising:
means for determining a second mode of operation for communication
from the second wireless terminal to the first wireless terminal as
a function of interference which will be caused in a base station
coverage area other than a base station coverage area in which said
second wireless terminal is located, said second mode of operation
being one of said direct mode of operation and said infrastructure
mode of operation; and means for communicating to the second
wireless terminal the determined second mode of operation to be
used for communication from the second wireless terminal to the
first wireless terminal.
16. The communications device of claim 13, wherein said second
wireless terminal is located in the second base station coverage
area.
17. The communications device of claim 15, wherein said means for
communicating to the first wireless terminal the determined first
mode of operation, include means for transmitting the determined
first mode of operation to the first wireless terminal via a first
base station included in the first base station coverage area.
18. The communications device of claim 13, wherein said means for
determining said first mode of operation include means for
determining the first mode as a function of interference which will
be caused in a base station coverage area other than a base station
coverage area in which said second wireless terminal is located, if
the determined first mode is used for communication from said
second wireless terminal to the first wireless terminal.
19. A computer program product for use in a communications device,
comprising: a non-transitory computer readable medium comprising:
code for causing at least one computer to determine a first mode of
operation for communication from a first wireless terminal, located
in a first base station coverage area, to a second wireless
terminal as a function of interference which will be caused in a
second base station coverage area adjacent said first base station
coverage area, said first mode of operation being one of a direct
mode of operation and an infrastructure mode of operation; and code
for causing the at least one computer to communicate to the first
wireless terminal the determined first mode of operation to be used
for communication from the first wireless terminal to the second
wireless terminal.
20. The computer program product of claim 19, wherein the
non-transitory computer readable medium further comprises: code for
causing the at least one computer to receive interference
information from a second base station, said interference
information including at least one of: i) interference information
determined by said second base station from a signal received by
said second base station from the first wireless terminal and ii)
interference information determined by a third wireless terminal in
the second base station coverage area which was reported to said
second base station.
Description
FIELD
[0001] Various embodiments relate to wireless communications
methods and apparatus and, more particularly, to wireless
communications methods for determining a communications mode to
use, e.g., a direct or an infrastructure communications mode,
and/or using a determined communications mode to communicate.
BACKGROUND
[0002] With the advancement of technology, communications systems
are becoming more and more diverse. For example, communications
devices which support various different communications technologies
and protocols can now operate in a communications system, e.g.,
network, and may communicate with each other, e.g., using a direct
mode of communication such as peer to peer communication or using
an infrastructure mode of communication, e.g., with communication
between the devices being achieved with signals being communicated
via another device such as a base station.
[0003] Generally in peer-to-peer communications, peer devices
discover each other and subsequently establish peer-to-peer
communications through direct signaling between the devices,
without any intervention from a centralized controller. This is
sometimes referred to as an infrastructure-less approach. Some
devices may support both peer-to-peer communications and
infrastructure based communications, e.g., communications via a
base station.
[0004] Thus, in a single communications network, some
communications devices may use peer to peer signaling to directly
communicate with one another, while others may communicate in an
infrastructure mode of operation, e.g., communicating via a base
station.
[0005] Individual wireless terminals may decide what mode of
operation to operate in, at a given time, e.g., a peer to peer mode
or an infrastructure mode of operation, e.g., based on the mode the
wireless terminal believes will create an acceptable level of
interference to other devices. Unfortunately, an individual
wireless terminal may have a limited understanding of its
surroundings. Thus a wireless terminal may not fully appreciate the
interference effects it may have on one or more devices, which the
wireless terminal may or may not be aware of, when making a
decision with regard to the mode of operation that should be used
at a particular point in time. As a result of the limited
information available to wireless terminals, individual devices
and/or pairs of devices seeking to communicate may not be able to
determine which communications mode of operation, e.g., direct mode
or infrastructure mode, is the most suitable mode for communicating
and/or which mode of communications is likely to have the biggest
impact on overall throughput of devices operating in a geographic
area. Thus, it should be appreciated that decisions made by an
individual wireless terminal or a pair of wireless terminals may be
suboptimal from an overall system perspective. The problem of a
wireless terminals limited knowledge of the overall system and
potential interference effects can be particularly significant
where the wireless terminal is in a region where the wireless
terminal's transmission may interfere with communications in
multiple cells of which the wireless terminal may have little or
limited knowledge in some cases.
[0006] From the above, it should be appreciated that individual
wireless terminals often lack the ability to see the larger picture
in terms of total interference implications from their mode
decision. Thus, if wireless terminals are left to make
determinations regarding the mode of operation the decision may be
suboptimal in overall system performance.
[0007] While providing wireless terminals greater information about
a network and potential interference implications of their mode
selection decisions, factors which affect interference such as the
location of mobiles within cells, cell loading, etc. can change
frequently making it difficult to distribute such information to
large number of devices in a timely manner. Furthermore,
communicating significant amounts of interference related
information to wireless terminals to facilitate mode decision
determinations can consume valuable resources.
[0008] In view of the above discussion it should be appreciated
that it would be beneficial if methods and/or apparatus could be
developed which would facilitate determination of a suitable mode
of operation for communications devices such that the mode
determination process takes into consideration the effect of a mode
of operation on various devices and/or cells without having to
provide large amounts of network interference information to
wireless terminals on a frequent basis.
SUMMARY
[0009] Methods and apparatus for determining the mode of wireless
communications to be used by a wireless terminal and/or using a
determined communications mode are described. In at least some
exemplary embodiments a communications device, e.g., wireless
terminal, can communicate with another communications device, using
either a direct mode of communication, e.g., using peer to peer
signaling, or an infrastructure mode of communication, e.g., a mode
in which communication occurs via an infrastructure element such as
a base station. In some embodiments, the mode to be used is
determined by a control node, e.g., a communications control sever,
discovery server, or another device, based on interference which
will be caused by the communication in an area, e.g., cell, in
which the wireless terminal seeking to communicate is not located.
Thus, in accordance with at least one feature, a control device
takes into consideration the interference which will be caused to a
base station coverage area, e.g., cell, in which at least one of
the devices seeking to communicate is not located. The interference
which may be caused within a cell in which the device seeking to
communicate may also be considered by the control device in making
the mode determination. By taking into consideration the effect of
the interference caused to multiple cells, the control device can
make a decision which takes into consideration the effect of the
communication on devices and network elements located outside the
cell in which an individual device seeking to communicate is
located. Thus, the mode may be selected to minimize overall system
interference and may be based on information which may not be
readily available to the wireless terminal seeking to communicate
and which may not even be available to a base station in a cell in
which a wireless terminal is located.
[0010] Interference cost estimates may, and do, correspond to
different frequency bands when the direct communications mode uses
a different frequency band than the infrastructure communications
mode. Thus, at least in some embodiments, a direct communications
mode interference cost estimate corresponding to a first frequency
band is compared to an infrastructure communications cost estimate
corresponding to a second frequency band which is different from
the first frequency band. The selected communications mode may, and
in some embodiments is, the mode with the lower interference cost
estimate.
[0011] By having the mode determination controlled by a control
device, e.g., centralized controller, the mode determination may,
and often does, take into consideration system wide interference
costs, e.g., interference costs relating to multiple cells, without
the need to distribute the information used to make the decision to
wireless terminals and/or multiple base stations. Thus, the
centralized mode determination approach used in various embodiments
can result in a more efficient use of resources by managing
interference taking into consideration system wide interference as
opposed to simply interference within a single cell.
[0012] While the communications channel between two devices may be
relatively symmetric, the interference cost to other devices in a
system may depend in large part on which device in a pair of
communicating devices is transmitting and the transmitting devices
proximity to other devices. Thus, the interference cost to a system
may be different in for each direction of communication. In various
embodiments, the communications mode is determined separately for
each direction of communication. Thus, in some embodiments the mode
selected for communicating from device A to device B may be
different from the mode selected for communicating from device B to
device A. For example, in one such embodiment, a first device may
be instructed to use peer to peer communication for communication
to a second device and to use infrastructure mode for
communications from the second device to the first device.
[0013] While the mode of communication is determined on a per
direction basis in some embodiments, in other embodiments a single
mode determination is made and the single mode is used for
communication in both directions.
[0014] The mode of communication selected by the control node may
be communicated to both devices which are seeking to communicate
via base station transmissions. In other embodiments, the mode is
communicated to one of the devices in a pair of communications
devices seeking to communicate, and the informed device
communicates the determined mode to the other device, e.g., via a
peer to peer signal when the selected mode is a peer to peer mode
or via a base station when the selected mode is an infrastructure
mode.
[0015] Among the described methods and apparatus are methods and
apparatus for operating a control device, e.g., network node, to
determine a first mode of operation for communication from a first
wireless terminal, located in a first base station coverage area,
to a second wireless terminal as a function of interference which
will be caused in a second base station coverage area adjacent said
first base station coverage area, said first mode of operation
being one of a direct mode of operation and an infrastructure mode
of operation, and to communicate to the first wireless terminal the
determined first mode of operation to be used for communication
from the first wireless terminal to the second wireless terminal.
In some embodiments, the second wireless terminal is located in the
second base station coverage area. The determination of the mode of
operation to use may be a function of interference which will be
caused by said communication to multiple cells.
[0016] One exemplary communications device comprises: at least one
processor configured to: determine a first mode of operation for
communication from a first wireless terminal, located in a first
base station coverage area, to a second wireless terminal as a
function of interference which will be caused in a second base
station coverage area adjacent said first base station coverage
area, said first mode of operation being one of a direct mode of
operation and an infrastructure mode of operation, and communicate
to the first wireless terminal the determined first mode of
operation to be used for communication from the first wireless
terminal to the second wireless terminal. The communications device
may, and in some embodiments does, include a memory coupled to the
at least one processor.
[0017] In addition to exemplary methods and apparatus, various
aspects are directed to a computer program product for use in a
communications device, comprising a computer readable medium
comprising code for causing at least one computer to determine a
first mode of operation for communication from a first wireless
terminal, located in a first base station coverage area, to a
second wireless terminal as a function of interference which will
be caused in a second base station coverage area adjacent said
first base station coverage area, said first mode of operation
being one of a direct mode of operation and an infrastructure mode
of operation, and code for causing the at least one computer to
communicate to the first wireless terminal the determined first
mode of operation to be used for communication from the first
wireless terminal to the second wireless terminal.
[0018] While various embodiments have been discussed in the summary
above, it should be appreciated that not necessarily all
embodiments include the same features and some of the features
described above are not necessary but can be desirable in some
embodiments. Numerous additional features, embodiments and benefits
of various embodiments are discussed in the detailed description
which follows.
BRIEF DESCRIPTION OF THE FIGURES
[0019] FIG. 1 illustrates an exemplary wireless communications
system, and communications between various devices in the system in
accordance with one embodiment.
[0020] FIG. 2 illustrates another exemplary communications system
implemented in accordance with another exemplary embodiment.
[0021] FIG. 3 is a more detailed example of a wireless
communications system in accordance with an exemplary
embodiment.
[0022] FIG. 4 illustrates communications between two communications
devices which may occur in the system shown in FIG. 3, in which a
direct, e.g., peer to peer, communications mode of operation is
used.
[0023] FIG. 5 illustrates communications between two devices which
may occur in the system shown in FIG. 3 when an infrastructure mode
of operation is used for communications between the two
devices.
[0024] FIG. 6 illustrates yet another example of communications
between two devices which may occur in the system shown in FIG. 3
but with a direct mode of communications operation being used in
one direction and an infrastructure mode of communication operation
in the reverse direction as may occur in some exemplary
embodiments.
[0025] FIG. 7A, which is a first part of FIG. 7, is a flowchart
illustrating an exemplary method of operating a control device, in
accordance with one exemplary embodiment.
[0026] FIG. 7B, which in combination with FIG. 7A comprises FIG. 7,
illustrates a second part of the exemplary method of operating a
control device in accordance with one exemplary embodiment.
[0027] FIG. 8 illustrates an exemplary control device which can be
used as the control node shown in the exemplary system shown in
FIGS. 3-6.
[0028] FIG. 9A illustrates a first portion of an assembly of
modules which can be used in the exemplary control device shown in
FIG. 8.
[0029] FIG. 9B illustrates a second portion of an assembly of
modules which can be used in the exemplary control device shown in
FIG. 8.
DETAILED DESCRIPTION
[0030] FIG. 1 illustrates a communications system 10 including a
base station A 12, a discovery server 14, a communications control
server 16 and a plurality of communications devices including
wireless terminals WT 1 18 and WT 2 20. In the FIG. 1 example, both
wireless terminals 18, 20 are located in the base station coverage
area 11 corresponding to base station A 12. The base station
coverage area 11 is sometimes referred to as the cell in which base
station A 12 is located. Thus, for purposes of discussion a base
station coverage area will be referred to as a cell. While not
shown in FIG. 1 the system 10 may, and normally does, include
multiple base stations as is the case shown in FIG. 2.
[0031] In the FIG. 1 embodiment communications devices, e.g.,
wireless terminals 18, 20 each communicate with the exemplary
discovery server 10, e.g., via a base station such as base station
A 12, to provide its location as well as the expressions, e.g.,
discovery information, that the device 18, 20 would like to
advertise and/or to monitor. This information may be updated by the
individual devices 18, 20 upon changes, e.g., as the devices 18, 20
change location and/or the users of the devices indicate a change
in preferences, devices or information which is to be discovered.
When the expressions of two devices 18, 20 within some proximity of
each other match, the discovery server 14 may, and normally does,
alert one or both devices 18, 20 to enable the devices and/or users
thereof to decide whether to establish a communication path to
further exchange traffic.
[0032] Location information as well as information about which
device pairs are seeking a communication path between them, is
provided to, e.g., a control device, e.g., communications control
server 16 which may be implemented as a node in the communications
system 10. The communication control server 16 may determine, e.g.,
based on system interference considerations, whether a
communication path between two devices, e.g., wireless terminals 18
and 20, should occur via an infrastructure element such as base
station 12 or via a direct peer-to-peer link. The decision may be
made on a per direction basis. In the FIG. 1 example, the
communications control server control 16 determines whether two or
more devices, will communicate using a direct communications mode
of operation or an infrastructure mode of communication operation.
While the communications control sever 16 and discovery server 14
are shown in FIG. 1 as individual nodes, the functions of the two
servers may be implemented in a single node which provides both
discovery and control functionality to the system 10.
[0033] In the example of FIG. 1, the wireless terminal WT 1 18 can
communicate with wireless terminal WT 2 20 through intermediate
base station 12. However, direct peer-to-peer communications is an
alternative possibility as illustrated by the dashed link 25.
Communications control sever 16 has knowledge of the topology of
the system 10, e.g., location of neighboring cells, and receives
interference information, cell loading information, and/or other
information useful in generating interference cost estimates and
predicting the interference which will be caused in the system due
to communications between devices. Communications control server 16
determines, based on one or more factors, e.g., system interference
cost estimates, whether the two devices 18, 20 are to operate in a
direct mode of operation or a peer to peer mode of operation at a
given point in time. The determination may be made by the control
server 16 generating an interference cost estimate for each
possible communications mode of operation and selecting the
communications mode having the lowest interference cost estimate
from a system perspective. Thus, the communications control server
16, in some embodiments, receives information from multiple cells
and takes into consideration the interference effect to not just
one cell but multiple cells when making the mode determination. The
mode of operation to be used, which is determined by the
communications control sever 16, is communicated to the wireless
terminals, e.g., via one or more messages sent by base station A.
The determination of which mode of operation is to be used may be
based, at least in part, on the interference the communication
between wireless terminals 1 and 2 (18, 20) will have on a
neighboring base station.
[0034] In the case where both terminals 18, 20 are in the same
cell, the wireless terminals 18, 20 and base station 12 within the
cell 11, may have a reasonable understanding of the interference
the communication between the two devices 18, 20 may cause at least
in the cell 11 in which the two devices 18, 20 are located.
However, the base station 12 and wireless terminals 18, 20 normally
do not include the full set of detailed information available to
communications control server 16 reported by multiple cells and/or
the full set of network topology information stored in
communications control server 16. Thus, the individual wireless
terminals and base station 12 may lack the detailed information
available to the communications control server 16 for making the
interference cost determinations. In some but not necessarily all
embodiments, the communications control server 16 keeps track of
which devices are communicating using a particular mode of
operation, there location, and the frequency band being used for
the communications. In this manner, the communications control
sever 16 may, and in some embodiments does, take into consideration
that peer to peer communications may, and in some cases are,
affected differently than infrastructure communications and factor
that into the interference cost estimate(s) used for selecting the
mode of communication to be used by a particular pair of devices
seeking to communicate.
[0035] FIG. 2 shows a more detailed illustration 50 of the system
shown in FIG. 1 with an additional base station, e.g., base station
B 22 shown in addition to base station A 12. In the FIG. 2 example
WT 1 18 is shown in cell 11 while WT 2 20 is shown in cell 13
corresponding to base station B 22. It should be appreciated that
FIG. 2 may correspond to a different point in time than the FIG. 1
example, e.g., a point in time following a move by WT 2 from the
first cell 11 to the second cell 13. In the FIG. 2 example WT 1 18
and WT 2 20 have connections to different base stations, e.g., base
station A 12 and base station B 22, respectively. Base stations 12,
22 are connected together via a backhaul link 15. Both base
stations 12, 22 are also coupled to the discovery server 14 and
communications control server 16 as shown.
[0036] As in the FIG. 1 example, the communications control sever
16, in response to a message indicating that WT 1 18 and WT 2 20
are seeking to establish a communications session, will determine
which mode of operation the devices 18, 20 should use for
communication and signal the mode to the devices. When an
infrastructure mode is selected, the devices will communicate via
base stations A and B 12, 22 while when a direct mode is selected,
they will communicate directly with each other as indicated by
dashed lines 55. As should be appreciated, the communications
control server 16 may determine that different modes of
communication should be used for different direction of
communication depending on the interference cost estimates. However
in some cases the control server 16 determines that the same mode
should be used for communications in each direction or a single
mode is selected and used by default for both directions.
[0037] Thus in some embodiments such as the ones discussed in FIGS.
1 and 2 examples, the decision maker is the communication control
server 16 which instructs the infrastructure node(s), e.g., base
station(s), that are currently serving the two wireless terminals
18, 20 and/or the devices including the wireless terminals 18, 20
regarding the communications mode and/or path which should be used
for communications. The instructions from the communications
control sever 16 to the wireless terminals 18, 20 may be
communicated via the base stations 12, 22. In some embodiments the
mode decision may, and in some cases is, based on 1) the geographic
location information of the two devices, 2) signal strength
measurement between the two devices, and/or 3) signal strength
and/or other information relating to other devices that have
already established peer-to-peer communication in the vicinity of
one or more of the devices 18, 20 seeking to establish a
communications session. The decision may further be based on a
comparison of the airlink cost of supporting the two connections
formed via one or more base stations (e.g., base station A 12 and
base station B 22 in the example) and that of the direct
peer-to-peer communication. In some embodiments interference caused
into a cell other than the cell in which the transmitting or
receiving device is located is taken into consideration. In some
embodiments the peer-to-peer communication may occur in a different
bandwidth from the infrastructure mode communications or share the
same bandwidth. In the latter case, in some embodiments the
decision maker, e.g., communications control sever 16, estimates
the potential interference the peer-to-peer connection may cause to
other ongoing infrastructure based communications. Note that the
discovery server 14 and communication control server 16 are
functionalities that may be, and in some embodiments are, combined
and/or co-located. Thus in some embodiments a control node which
provides the functions of both the discovery server 14 and
communications control server 16 is implemented and used in the
system.
[0038] FIG. 3 illustrates an exemplary communications network 100,
implemented in accordance with one exemplary embodiment. Exemplary
communications network 100 includes a plurality of wireless
communications devices, e.g., mobile wireless terminals, including
wireless terminal 1 102, wireless terminal 2 104, wireless terminal
3 106, . . . , wireless terminal K 108, and wireless terminal N
110. As illustrated, the communications network 100 further
includes one or more base stations including base station (BS) 1
112, base station 2 114, base station 3 116, each one having a
corresponding base station coverage area as represented by the
circles 118, 120 and 122. Circles 118, 120 and 122 correspond to
the cell in which the respective base station 118, 120, 122 is
located. Although each base station coverage area has been shown as
a single sector cell in FIG. 3, in some embodiments, some or all of
the base station coverage areas or cells of the network 100 may be
multi-sectored. Each cell 118, 120, 122 may include a plurality of
wireless terminals that can exchange information with the cell's
base station (BS) via, e.g., wireless links.
[0039] The communications network 100 includes a central control
device, e.g., the control node 124 which is coupled to the base
stations 118, 120, 122 in the network 100, e.g., via network links
113, 115, 117. The control node 124, in some embodiments is also
coupled to the Internet and other network nodes via one or more
additional links. The network links may be, e.g., fiber optic
links. In some embodiments the control node 124 may be implemented
as a central element of the network 100 which can support and
communicate with a plurality of base stations in the network
100.
[0040] The communications devices 102, 104, 106, 108, 110, may be,
e.g., mobile terminals, which support direct peer to peer
communications as well as communications via one or more base
stations. Exemplary communications network 100, in some embodiments
may also include other devices such as a discovery server 14, etc.
The wireless communications devices 102, 104, 106, 108, and 110
support various signaling between peers, e.g., peer discovery
signals, transmission request signals etc., and data transmissions.
The communications devices 102, 104, 106, 108, 110 also support
communications with infrastructure elements such as the control
node 124, and base stations 112, 114, 116.
[0041] Some of the communications devices 102, 104, 108 are mobile
communications devices, e.g., handheld mobile communications
devices, while some others may be fixed devices in at least one
embodiment. In the FIG. 3 example, WT 1 102 is shown to be
transmitting signals, e.g., pilot, beacon, and/or one or more peer
discovery signals 125 which are transmitted at a predetermined
power level. Signals 125 can, and in various embodiments are,
received by other devices in the system, and the received signal
strength measured and reported to the control node 124 for use in
generating interference estimates. In addition to the wireless
terminals' transmitting signals at known power levels, devices
including, e.g., base stations 112, 116 and 114 may also transmit
such signals, e.g., pilots, beacons and/or other signals which can
be measured and used for interference estimation purposes.
[0042] In accordance with one aspect, communications devices in
network 100 may communicate with one another using either a direct
mode of operation, e.g., a peer to peer mode of communication
operation, or an infrastructure mode, e.g., a mode of operation
where communications is done via one or more base station. In some
embodiments the decision as to which one of the two modes of
operation a device should use for communications, is made by the
control node 124, as a function of one or more factors including,
e.g., one or more system interference cost estimates. The
interference cost estimates may be generated based on location and
proximity of the communicating devices, an expected transmission
power level that the transmitting device is expected to use for
transmitting signals to another device with which the transmitting
device is trying to communicate and/or other information including
information on the received signal strength of pilot, beacon or
peer discovery signals reported to the control node along with
information indicating the source of the received signal and the
device providing the received signal strength information.
[0043] In accordance with one embodiment, it is possible that based
on one or more factors including, e.g., system interference cost
estimate, the control node 124 may direct one or more devices,
e.g., wireless terminals 102, 104 which are seeking to communicate,
to use a direct mode of operation for communications, e.g., using
peer to peer signaling. For example, if the control node 124
determines that the communications devices 102, 104 are
sufficiently close to each other the control node 124 may decide
that it may be more efficient, from an overall system interference
perspective, for the communications devices 102, 104 to communicate
directly rather than communicate via one or more base stations. In
such a scenario, the control node 124 may, and in some embodiments
does, instructs the devices 102, 104, via the base stations 112,
116 to communicate with each other directly without the need of one
or more base stations to be involved in the communication between
the two devices in terms of relaying or forwarding information or
signals. It should be appreciated that the determination regarding
the suitable mode of operation in some embodiments, is
independently made for each direction of communication, for
example, a first determination may be made for communications from
WT 1 102 to WT 2 104 and a second independent determination may be
made with regard to the mode of communication to be used for
communications from WT 2 104 to WT 1 102. In such embodiments, the
determined mode of operation may be different in each direction. In
other embodiments, a single determination is made and the selected
mode of operation is used for communications in both directions
between WT 1 102 and WT 2 104.
[0044] FIG. 4 is a drawing 200 illustrating an example showing
communications between two communications devices 102, 104 in the
system shown in FIG. 3, using a direct mode of operation in both
directions, in accordance with one exemplary embodiment.
[0045] In the FIG. 4 example, wireless terminal WT 1 102 in the
first base station coverage area 118 is shown communicating with
another wireless terminal, i.e., WT 2 104 after being instructed by
the control node 124 to communicate in such a manner, e.g., in
response to receiving a message or other indication that the first
and second wireless terminals 102, 104 are seeking to
communicate.
[0046] FIG. 5 is a drawing 300 illustrating an exemplary scenario
in which two communications devices of network 100 are
communicating using an infrastructure mode of operation, in
accordance with one exemplary embodiment, for communication in both
directions between the two wireless terminals WT1 102 and WT 2 104.
Such communication may follow the control node 124 directing WT1
102 and WT 2 to communicate in both directions using infrastructure
mode operation to communicate, e.g., because one or more
interference cost estimates indicated that this was the most
efficient communications mode from a system interference cost
perspective. In such a scenario, the devices 102, 104 communicate
with each other via one or more base stations 112, 116 and/or the
backhaul network interconnecting the base stations.
[0047] The communications from WT 1 102 to WT 2 104, via base
station 1 112 and base station 3 116 are shown using arrows 132,
134 and 136. Thus in this example, using the infrastructure mode
the information and/or data may be transmitted from WT 1 102 to
base station 1 112 (as represented by arrow 132), the base station
1 112 can send the communicated information to the base station 3
116 which is currently serving the area where WT 2 102 is located,
via backhaul (represented by 134) and finally base station 3 116
communicates the information to WT 2 104 (represented by arrow
136). In this particular example, it is assumed that the determined
second mode of operation for the reverse direction i.e., from WT 2
104 to WT 1 102, is also the infrastructure mode of operation. Thus
communications in the reverse direction using infrastructure mode
of operation are shown using arrows 137, 139 and 140.
[0048] FIG. 6 is a drawing 400 illustrating yet another exemplary
scenario in which communications from a device, e.g., WT 1 102 to a
second device, e.g., WT 2 104, is achieved using an infrastructure
mode of operation while in communications in the reverse direction,
i.e. from WT 2 104 to WT 1 102 is done using a direct mode of
operation. Such a communications scenario occurs when the control
node 124 direct the communicating devices 102, 104 to use an
infrastructure mode in one direction (e.g., from WT 1 102 to WT 2
104) while directing the communicating devices 102, 104 to use
direct peer to peer mode of operation in the reverse direction
(e.g., from WT 2 104 to WT 1 102). This may occur, e.g., when a
comparison made by the control node 124 indicates that a direct
communications mode interference cost estimate to an infrastructure
mode cost estimate for communications from WT 1 102 to WT 2 reveals
that use of infrastructure mode communications mode for
communications from WT 1 to WT 2 results in less interference cost,
in terms overall interference cost to the systems, than direct mode
compunctions. However, in this example with regard to the reverse
direction, the control node 124 selected the direct mode for the
communications from WT 104 to WT 1 102 since the interference cost
estimates for direct and infrastructure mode communications
indicated that direct mode communication was preferable from a
system interference perspective for communications from WT 2 104 to
WT 1 10. and infrastructure interference cost estimates for
communication from WT 1, 102 to WT 2 104.
[0049] While some examples discussed above have been used to
describe various features, the method used in some embodiments will
become even clearer when considered in view of the flow chart shown
in FIG. 7.
[0050] FIG. 7, which comprises the combination of FIGS. 7A and 7B,
is a flowchart 700 showing the steps of an exemplary method of
operating a control device, in accordance with an exemplary
embodiment. The control device can be, e.g., the control node 124
shown in FIG. 3. To facilitate better understanding of the method
700, reference to FIGS. 3-6 maybe made.
[0051] As shown in FIG. 7A, operation starts in step 701. In step
701 the control node 124 is powered on, initialized and begins
monitoring for messages and/or other signals. Each of the arrows
extending out of step 701 corresponds a processing path associated
with a different type of signal or information which may be
received. Thus, operation proceeds from start step 701 along three
parallel paths, to steps 702, 704 and 710 respectively. In some
embodiments steps 702, 703 and 710 may occur asynchronously, e.g.,
in parallel. In step 702 the control node 124 receives network
topology/configuration information which provides information
regarding the configuration of the network 100. The operation
proceeds from step 702 to step 703 where the received network
topology information is stored, e.g., in a memory. Operation
proceeds from step 703 back to step 702 where the control node 124
waits to receive further topology updates. Network topology
information, e.g., base station location, sectorization and
frequency band usage information may be updated in response to
changes in the system such as the addition or elimination of a base
station and corresponding cell. Network topology information is
stored for future use, e.g., in generating interference cost
estimates. The network topology information may provide information
on adjacent cells and thus which cells should be considered when
generating an interference cost estimate based on expected
transmissions in a cell. Network topology information may also
include information on the frequency band or bands to be used for
peer to peer signaling in different locations in the system. For
example, in some cells, the frequency band used for direct, e.g.,
peer to peer communication, is different from the frequency band
used for infrastructure mode communications. In other embodiments
and/or in some cells, the infrastructure mode and direct mode may
use the same frequency band for communications purposes. The
frequency band to be used for direct and infrastructure mode
communications is stored as part of the network topology
information, e.g., on a per cell and/or per sector basis.
[0052] In addition to receiving and storing network related
topology information, the control node may receive and store
interference information which may, and in some embodiments is,
used to generated interference cost estimates. The receipt and
storage of interference information may occur over a period of
time, e.g., in parallel with the updating and storage of network
topology information and the actual generation and use of
interference cost estimates as part of a communications mode
determination process.
[0053] In step 704 the control node 124 receives interference
information from base stations and/or wireless terminals. In step
704 pilot, beacon and/or other signal measurement information,
e.g., the results of signal measurements made by wireless terminals
and/or base stations may be received by the control node. Beacon
ratio reports and transmission power level information may also be
received. This information can be used in predicting the
interference cost of a particular mode of operation under
consideration, e.g., direct or infrastructure mode.
[0054] Step 704 includes step 705 of receiving interference
information from a second base station, e.g., base station 2 114,
said interference information including at least one of i)
interference information determined by the base station 2 114 from
a signal received by the base station 2 114 from the first wireless
terminal 1 102, and ii) interference information determined by a
third wireless terminal in a second base station coverage area,
e.g., coverage area 120, which was reported to the second base
station 2 114.
[0055] Consider for example, the system shown in FIG. 3. Base
station 2 114 which is located adjacent the base station coverage
area 118 where WT 1 102 is located, receives signal 125 which may
be, e.g., a pilot or beacon signal broadcast by the WT 1 102. The
base station 2 114 may measure the strength of the received signal
which, from second base station's perspective is interference from
the neighboring cell due to transmissions by WT 1 102. The received
signal strength of the signal transmitted at a known power level,
e.g., pilot signal or control channel signal transmitted at a
controlled known power level, can be used to predict interference
which will be caused by transmission by WT 1 at other power levels,
e.g., power levels expected for peer to peer or infrastructure mode
transmissions. It should be appreciated that although base station
2 114 is being considered as the second base station in this
example, another base station, e.g., base station 3 116, which is
adjacent the base station coverage area 118 where WT 1 102 is
located may and in some embodiments does also take and report
various measurements to the control node. Such measured values
and/or reports represent interference information which can be used
by the control node in generating interference cost estimates. In
some embodiments the interference information is generated by a
third wireless terminal, e.g., WT N 110 in coverage area 120, WT 2
104 in the coverage area 122, which measures received signals and
reports the measurement results to the base station serving the
cell where the wireless terminal making the interference
measurements is located. For example, WT N 110 reports interference
measurements to base station 2 114 which uses them and relays them
to the control node 124. WT 2 104 makes the interference
measurements and reports the interference measurements to base
station 3 116. The base stations 112, 114, 116, communicate all or
some of the received interference information to the control node
124. In some embodiments interference information reported by
wireless terminals is in the form of a beacon ratio report which
may be a report of the measured strength of a beacon or pilot from
one base station relative to the measured strength of beacon or
pilot from another base station. Such interference reports provide
an indication of the relative channel condition from the wireless
terminal to the base stations from which the beacons signals used
to generate the report were receive and can be used in predicting
interference that will be generated by the wireless terminal to the
base station or base stations.
[0056] In some embodiments step 704 further includes an optional
step 706 as indicated in the flowchart by the dashed box, and is
performed in some embodiments while skipped in other embodiments.
In step 706 the control node 124 receives interference information
from a base station, e.g., from base station 2 114 or base station
1 112, outside the coverage area where the second wireless terminal
WT 2 104 is located, said information including at least one of: i)
interference information determined by said base station from a
signal received by said base station from the second wireless
terminal WT 2 104, and ii) interference information determined by
another wireless terminal in the coverage area of said base station
which was reported to said base station.
[0057] The interference measurements may be made by several base
stations and/or wireless terminals operating in neighboring cells
in the network 100, periodically or non periodically, using
broadcast signals, e.g., pilot or beacon, from communications
devices which are trying to communicate with other devices in the
network 100. The interference information is then reported to the
control node 124. Operation proceeds from step 704 to step 708
wherein the received interference information is stored. Operation
proceeds from step 708 back to step 704 in which additional
interference information may be received and stored, e.g., on an
ongoing basis. Updated information for a particular wireless
terminal and/or base station may replace older information as the
new interference information is received and stored.
[0058] As noted above, in addition to receiving various types of
information useful in generating interference cost estimates, the
control node 124 is also responsible for receiving and processing
messages indicating that devices are seeking to establish
communication with each other and for responding with information
indicating the mode of operation, direct mode or infrastructure
mode, which should be used for the communication. Receive step 710
marks the start of the processing path associated with messages
relating to communications establishment between a pair of
devices.
[0059] In step 710 the control node 124 receives a message
indicating and intent or desire to establish communications between
devices, e.g., between a first wireless terminal, e.g., WT 1 102
and a second wireless terminal, e.g., WT 2 104. In some embodiments
WT 1 102 may communicate such a request received in step 710 to the
control node 124 through the serving base station 1 112. In other
embodiments, the message indicating an intent or desire to
establish a communications session may come from a node such as the
peer discovery server 14 which may determine that two nodes in the
vicinity of one another are of interest to one another and may want
to communicate. Operation proceeds from step 710 to step 722 via
connecting node A 720.
[0060] In step 722 the control node 124 determines a first direct
mode system interference cost estimate based on the stored
interference information. The first direct mode system interference
cost estimate is an estimate of the interference cost of the system
that will be caused if the nodes seeking to communicate are allowed
to communicate directly, e.g., in a first direction in embodiments
where separate unidirectional cost estimates are generated or
bi-directionally in cases where a single interference cost estimate
is generated for the purposes of bi-directional communications mode
decisions.
[0061] A system interference cost estimate, in some but not
necessarily all embodiments, is generated as a sum of individual
interference cost estimates generated for multiple cells or
coverage areas which are likely to be affected by the communication
session. Accordingly, in various embodiments, when a system
interference cost estimate is generated, it takes into
consideration the interference caused in multiple individual base
station coverage areas which will be caused by the mode of
operation for which the interference cost estimate is being
generated.
[0062] For example, a first direct mode system interference cost
estimate can be determined for communications from WT1 and WT2 by
calculating the sum of expected interference costs that may be
caused in each of the base station coverage areas 118, 120, 122, if
the WT 1 102 and the WT 2 104 communicate using direct mode of
operation, i.e., peer to peer communications.
[0063] A direct mode interference cost estimate may be generated
and expressed as a sum of interference cost estimates for the
different cells in the system which will be affected by the
communication.
[0064] Direct mode system interference cost estimate (DMSICE)
=.SIGMA..sub.i=1 to n(DMI.sub.cell i)=(DMI.sub.cell 1+DMI.sub.cell
2+ . . . +DMI.sub.cell n)
[0065] where DMI.sub.cell 1 represents Direct Mode Interference
Cost for Cell 1, DMI.sub.cell 2 represents Direct Mode Interference
Cost for Cell 2 and so on.
[0066] The interference cost for an individual cell may be
generated in a plurality of ways. Expected transmission power
levels may be taken into consideration in generating the
interference cost estimates in addition to various other factors
such as base station loading in one or more cells, the location of
the devices which will be transmitting, the sectorization or
antenna configurations of the base stations which are transmitting
and/or receiving, etc.
[0067] Operation proceeds from first direct mode system
interference cost estimation step 722 to step 724 which is a first
infrastructure mode system interference cost estimation step. In
step 724 the control node 124 determines a first infrastructure
mode system interference cost estimate, e.g., based on expected
interference caused to both the first base station coverage area
118 and the second base station coverage area 120 if the first
wireless terminal WT 1 102 and the second wireless terminal WT 2
104 communicate using infrastructure mode of operation, e.g.,
through a base station. If the system determines the communications
modes for the different directions independently, the first
infrastructure mode system interference cost estimate will be for a
single direction of communication operation while if the first
infrastructure mode system interference cost estimate will be used
for making a bi-directional communications the cost estimate may be
for bi-directional communications. The first direct mode system
interference cost estimate 722 is the counterpart to the first
infrastructure mode system interference cost estimate 724 with both
estimates being generated for the same communications case, e.g.,
uni-directional communications or bi-directional
communications.
[0068] In some embodiments, the system interference cost estimate
for the infrastructure mode is the sum of individual interference
cost estimates generated for individual cells or coverage
areas.
[0069] Infrastructure mode system interference cost estimate
(IMSICE)
IMSICE=.SIGMA..sub.i=1 to n(IMI.sub.cell i)=(IMI.sub.cell
1+IMI.sub.cell 2+ . . . +IMI.sub.cell n)
[0070] where IMI.sub.cell 1 represents Infrastructure Mode
Interference Cost for Cell 1 (e.g., expected interference cost to
cell 1 when WT 1 102 communicates with WT 2 104 using
infrastructure mode), I I.sub.cell 2 represents Infrastructure Mode
Interference Cost to Cell 2 and so on. The Infrastructure Mode
Interference Cost estimate for a cell may be generated using a
variety of techniques. For example, reported beacon ratio reports
and/or other information can be used to generate an Infrastructure
Mode Interference Cost estimate for a cell.
[0071] Direct mode and infrastructure mode system interference cost
estimates may, in some embodiments do, correspond to different
frequency bands. For example, when the direct communications mode
uses a first communications band which is different from a second
communications band used for infrastructure mode communication, the
direct communications mode and infrastructure communications mode
interference cost estimates will correspond to different frequency
bands. In some, but not necessarily all embodiments the
infrastructure mode frequency band is used to notify communications
devices, e.g., wireless terminals, of the communications mode to
use even if the direct communications mode is selected to be
used.
[0072] Operation proceeds from step 724 to step 726. In step 726
the control node 124 determines a first mode of operation for
communication, e.g., for communication from the first wireless
terminal to the second wireless terminal. Of course, in the case
where the terminals use the same mode for both directions as
opposed to separate mode determinations for each direction, the
determined first mode of operation is also to be used for
communication from the second wireless terminal to the first
wireless terminal.
[0073] In some embodiments the first mode of operation is selected
in step 726 by comparing the value of the first direct mode
interference cost estimate generated in step 722 to the value of
the first infrastructure mode system interference cost estimate
generated in step 724 and then selecting, in sub-step 727, the mode
corresponding to the lower of the two interference cost estimates
as the first mode of operation.
[0074] When one of the wireless terminals seeking to communicate is
in a different base station coverage area, e.g., cell than the
first wireless terminal. The interference cost estimates and
resulting mode determination will be a function of the interference
cost to multiple cells.
[0075] For example, consider when WT 1 102 located in the first
base station coverage area seeks to communicate to the second
wireless terminal WT 2 104. The mode determination is made as a
function of interference which will be caused in a second base
station coverage area adjacent said first base station coverage
area. The mode determination selects between one of the direct mode
of operation and the infrastructure mode of operation. In some
embodiments the first base station coverage area is a coverage area
of the first station 112 (i.e., coverage area 118) and the second
base station coverage area is the coverage area of the second base
station 114 located adjacent said first base station (i.e.,
coverage area 120). In some embodiments the second wireless
terminal WT 2 104 is located in the second base station coverage
area 120. In some embodiments the first and second wireless
terminals WT 102, 103 are located in the first base station
coverage area 118. In some embodiments the step of determining the
first mode of operation is a function of the direct mode system
interference cost estimate and an infrastructure mode system
interference cost estimate.
[0076] In some embodiments, the determined first mode of operation
is considered as a default mode of operation for communications
from the second wireless terminal WT 2 104 to the first WT 1 102.
In such embodiments, the first mode determination serves as a
bi-directional mode determination even though the decision may be
based on a set of uni-directional interference costs estimates
interference costs without the generation of a second set of cost
estimates for communication from the second wireless terminal WT 2
104 to WT 1 102.
[0077] In some such embodiments determining the first mode of
operation is a function of interference which will be caused in a
base station coverage area other than a base station coverage area
in which said second wireless terminal WT 2 104 is located.
[0078] Operation proceeds from step 726 to step 728 in cases where
a separate mode of operation determinations are made for each
direction of communication or directly to step 736 in embodiments
where a single mode of operation determination is made for both
modes of operation. Thus, steps 728, 730 and 732 are optional steps
which are skipped in some embodiments.
[0079] In step 728 the control node 124 determines a second direct
mode system interference cost estimate, e.g., an interference cost
estimate corresponding to communication from the second wireless
terminal WT 2 104 to the first wireless terminal WT 102.
[0080] The second direct mode system interference cost estimate may
be determined in the same or in a similar manner to the way in
which the first direct system cost estimate discussed earlier in
step 722 was generated but taking into consideration that the
second WT 2 104 will be the transmitting device for purposes of
determining the second direct mode system interference cost
estimate.
[0081] It should be appreciated that individual interference cost
estimates corresponding to communications from WT 2 104 to WT 1
102, for different areas or devices which may be summed to generate
the system interference cost estimate, are likely to be different
than those generated for communication in the other direction since
the devices in the proximity to the transmitting device WT 2 104,
which is the transmitting device for this interference
determination, are different than those in the immediate vicinity
of WT 1 102 which is the transmitter for communications from WT 1
102 to WT 2 104.
[0082] Operation proceeds from step 728 to step 730. In step 730
the control node 124 determines a second infrastructure mode system
interference cost estimate.
[0083] For example, in the FIG. 3 example the second infrastructure
mode system interference cost estimate may be based on, e.g., a sum
of, expected interference caused to both the first base station
coverage area 118 and the coverage area of base station coverage
area 122 where WT 2 104 is located assuming communication through a
base station. The second infrastructure mode system interference
cost estimate may, and in some embodiments is, determined in the
same or similar manner to the way in which the first infrastructure
mode system cost estimate is generated. Thus the second
infrastructure mode system interference cost estimate can be
determined by calculating the sum of expected interference costs
that may be caused in each of the base station coverage areas 118,
120, 122, if WT 2 104 communicates with WT 1 102 using
infrastructure mode, e.g., through one or more base stations as
shown in FIG. 5.
[0084] Operation proceeds from step 730 to step 732. In step 732
the control node 124 determines a second mode of operation for
communication from the second wireless terminal WT 2 104 to the
first wireless terminal WT 1 102. The second mode of operation is
one of a direct mode of communication operation and an
infrastructure mode of communication operation. The determination
may be made by comparing the interference cost estimates for the
direct and infrastructure modes of operation and selecting, e.g.,
in sub-step 734, the mode with the lower cost estimate.
[0085] In the FIG. 3 exemplary embodiment the determination is made
as a function of interference which will be caused in a base
station coverage area other than a base station coverage area in
which WT 2 104 is located. In the FIG. 3 example being discussed
the base station coverage area in which WT 2 104 is located is area
122. However in some other embodiments WT 2 104 could be located
elsewhere. Thus, in the present example, the determination of the
second mode of operation for communications from WT 2 104 to WT 1
102 is made as a function of the interference which will be caused
to the neighboring base station coverage area, e.g., in coverage
areas 118, 120. In some embodiments, determining the second mode of
operation is a function of the second direct mode system
interference cost estimate and the second infrastructure mode
system interference cost estimate.
[0086] Operation proceeds from step 732 which includes sub-step 734
to communication step 736.
[0087] In step 736 the control node 124 communicates to the first
wireless terminal WT 1 102 at least the determined first mode of
operation to be used for communication from the first wireless
terminal WT 1 102 to the second wireless terminal WT 2 104. In step
736, the control node 124 may, optionally, also communicate the
determined second mode of operation to be used for communication
from the second wireless terminal WT 2 104 to the first wireless
terminal WT 1 102. In some embodiments the step of communicating
the first determined mode of operation includes performing
transmitting 738 information, e.g., a message, indicating the
determined first mode of operation to the first wireless terminal
WT 1 102 via a base station. The transmission to WT 1 102 maybe,
for example, in the case of the FIG. 3 example, via base station
112 in the first base station coverage area 118.
[0088] Operation proceeds from step 736 to step 740. In step 740
the control node 124 transmits, to the second wireless terminal WT
2 104, information indicating the determined first mode of
operation. In cases where a second mode of operation was
determined, the determined second mode of operation may also be
communicated. Since a second mode may not be determined in all
embodiments, the communication of the determined second mode of
operation is optional and will not occur when a second mode of
operation is not determined.
[0089] In some embodiments transmitting to the second WT 2 104,
information indicating the determined first mode of operation is
via a base station. For example, in the FIG. 3 example the
transmission may be via base station 3 116 which serves the
coverage area 122 in which WT 2 104 is located. In some other
embodiments transmitting to the second WT 2 104, information
indicating the determined first mode of operation is via the first
wireless terminal, e.g., via a direct transmission from the first
wireless terminal WT 1 102 to the second wireless terminal WT 2
104. In a similar manner, information indicating the determined
second mode of operation for communications from WT 2 104 to WT 1
102 can be transmitted to the first wireless terminal WT 1 102 via
a base station, e.g., base station 1 112. In other embodiments the
communication maybe via a transmission from the second wireless
terminal WT 2 104 to the first WT 1 102, e.g., when the second mode
is to be a direct mode of communication.
[0090] Thus, the control node 124 ensures that the communications
devices that wish to communicate with one another are informed
about the suitable mode of operation to communicate in each
direction of communication before they start communicating. Thus,
the wireless terminals will communicate using a mode which is cost
effective from a system wide interference perspective.
[0091] With the communications devices seeking to communicate
having been informed of the mode of communications operation to
use, operation proceeds from step 740 back to 710 via connecting
node B 742 wherein the control node proceeds to receive and begin
processing another message indicating an intent to establish
communication between two wireless terminals.
[0092] FIG. 8 is a drawing of an exemplary communications device
800, e.g., a control node, in accordance with one exemplary
embodiment. Communications device 800 can be implemented as the
control node 124 shown in FIG. 3. In some embodiments
communications device 800 is a network device implementing a method
in accordance with flowchart 700 of FIG. 7. Communications device
800 includes a processor 802 and memory 804 coupled together via a
bus 809 over which the various elements (802, 804) may interchange
data and information. Communications device 800 further includes an
input module 806 and an output module 808 which may be coupled to
the processor 802 as shown. However, in some embodiments the input
module and output module 806, 808 are located internal to the
processor 802. Input module 806 can receive input signals. Input
module 806 can, and in some embodiments does, include a wireless
receiver and/or a wired or optical input interface for receiving
input. Output module 808 may include, and in some embodiments does
include, a wireless transmitter and/or a wired or optical output
interface for transmitting output.
[0093] Processor 802, in some embodiments, is configured to
determine a first mode of operation for communication from a first
wireless terminal, e.g., WT 1 102, located in a first base station
coverage area, to a second wireless terminal, e.g., WT 2 104 as a
function of interference which will be caused in a second base
station coverage area adjacent said first base station coverage
area, said first mode of operation being one of a direct mode of
operation and an infrastructure mode of operation, and communicate
to the first wireless terminal WT 1 102 the determined first mode
of operation to be used for communication from the first wireless
terminal WT 1 102 to the second wireless terminal WT 2 104. In some
embodiments the first base station coverage area is a coverage area
of a first base station and said second base station coverage area
is a coverage area of a second base station located adjacent said
first base station.
[0094] In some embodiments the processor 802 is configured to
receive network topology information and store the network topology
information. Processor 802 is further configured to receive
interference information from base stations and/or wireless
terminals. Processor 802 in some embodiments is further configured
to store the received interference information, e.g., in memory
804. The processor 802 is further configured to receive
interference information from the second base station, said
interference information including at least one of: i) interference
information determined by said second base station from a signal
received by said second base station from the first wireless
terminal and ii) interference information determined by a third
wireless terminal in the second base station coverage area which
was reported to said second base station.
[0095] Processor 802 is further configured to determine a direct
mode system interference cost estimate based on expected
interference, if the first and second wireless terminals
communicate using the direct mode of operation, to both the first
base station coverage area and the second base station coverage
area. The processor 802 is further configured to determine an
infrastructure mode system interference cost estimate based on
expected interference, if the first and second wireless terminals
communicate using the infrastructure mode, to both the first base
station coverage area and the second base station coverage area. In
some embodiments determining a first mode of operation is a
function of the direct mode system interference cost estimate and
the infrastructure mode system interference cost estimate.
[0096] In some embodiments the processor 802 is further configured
to select, as part of determining the first mode of operation, the
mode of operation having the lower determined system interference
cost estimate. In some embodiments the second wireless terminal WT
2 104 is located in the second base station coverage area, e.g.,
area 120. In some embodiments the first and second wireless
terminals are located in the first base station coverage area,
e.g., area 118.
[0097] Processor 802 in at least one embodiment is further
configured to determine a second mode of operation for
communication from the second wireless terminal WT 2 104 to the
first wireless terminal WT 1 102 as a function of interference
which will be caused in a base station coverage area other than a
base station coverage area in which said second wireless terminal
is located, said second mode of operation being one of said direct
mode of operation and said infrastructure mode of operation. The
processor 802 is further configured to communicate to the second
wireless terminal WT 2 104 the determined second mode of operation
to be used for communication from the second wireless terminal WT 2
104 to the first wireless terminal WT 1 102.
[0098] In some embodiments the processor 802 is further configured
to transmit the determined first mode of operation to the first
wireless terminal WT 1 102 via a first base station included in the
first base station coverage area. The processor 802 is further
configured to transmit, to the second wireless terminal WT 2 104,
information indicating the determined first mode of operation. In
some embodiments the processor 802 is configured to transmit to the
second wireless terminal WT 2 102 information indicating the
determined first mode of operation via a second base station.
[0099] In some embodiments determining the first mode of operation
is also a function of interference which will be caused in a base
station coverage area other than a base station coverage area in
which the second wireless terminal WT 2 104 is located, if the
determined first mode is used for communication from said second
wireless terminal WT 2 104 to the first wireless terminal WT 1
102.
[0100] FIG. 9, comprising the combination of FIG. 9A and FIG. 9B,
is an assembly of modules 900 which can, and in some embodiments
is, used in the control device, e.g., control node 800, illustrated
in FIG. 8. Assembly of modules 900 includes first portion 900A and
second portion 900B. The modules in the assembly 900 can be
implemented in hardware within the processor 802 of FIG. 8, e.g.,
as individual circuits. Alternatively, the modules may be
implemented in software and stored in the memory 804 of the
communications device 800 shown in FIG. 8. While shown in the FIG.
8 embodiment as a single processor, e.g., computer, it should be
appreciated that the processor 802 may be implemented as one or
more processors, e.g., computers.
[0101] When implemented in software the modules include code, which
when executed by the processor 802, configure the processor to
implement the function corresponding to the module. In embodiments
where the assembly of modules 900 is stored in the memory 804, the
memory 804 is a computer program product comprising a computer
readable medium comprising code, e.g., individual code for each
module, for causing at least one computer, e.g., processor 802, to
implement the functions to which the modules correspond.
[0102] Completely hardware based or completely software based
modules may be used. However, it should be appreciated that any
combination of software and hardware, e.g., circuit implemented
modules may be used to implement the functions. As should be
appreciated, the modules illustrated in FIG. 9 control and/or
configure the communications device 800 or elements therein such as
the processor 802, to perform the functions of the corresponding
steps illustrated in the method flow chart 700 of FIG. 7.
[0103] The assembly of modules 900 includes a module corresponding
to each step of the method shown in FIG. 7. The module in FIG. 9
which performs or controls the processor 802 to perform a
corresponding step shown in FIG. 7 is identified with a number
beginning with a 9 instead of beginning with 7. For example module
904 corresponds to step 704 and is responsible for performing the
operation described with regard to step 704. As illustrated in FIG.
9, the assembly of modules 900 includes a module 902 for receiving
network topology information, a module 703 for storing the network
topology information, a module 904 for receiving interference
information from base stations and/or wireless terminals, a module
908 for storing received interference information, and a module 910
for receiving a message indicating an intent to establish
communications between devices, e.g., between a first wireless
terminal and a second wireless terminal. The module 904 includes a
module 905 for receiving interference information from a second
base station, said interference information including at least one
of: i) interference information determined by the second base
station from a signal received by the second base station from the
first wireless terminal and ii) interference information determined
by a third wireless terminal in a second base station coverage area
which was reported to the second base station. In some embodiments
module 904 further includes an optional module 906 for receiving
interference information from a base station which is outside the
coverage area where the second wireless terminal is located, the
interference information including at least one of: i) interference
information determined by said base station from a signal received
by the base station from the second wireless terminal and ii)
interference information determined by another wireless terminal in
the coverage area of said base station, which was reported to said
base station.
[0104] In some embodiments the assembly of modules 900 further
includes a module 922 for determining a first direct mode of system
interference cost estimate based on expected interference, if the
first and second wireless terminals communicate using a direct mode
of operation, to both a first base station coverage area and the
second base station coverage area, a module 924 for determining a
first infrastructure mode of system interference cost estimate
based on expected interference, if the first and second wireless
terminals communicate using an infrastructure mode of operation, to
both the first base station coverage area and the second base
station coverage area, and a module 926 for determining a first
mode of operation for communication from the first wireless
terminal, located in the first base station coverage area, to the
second wireless terminal as a function of interference which will
be caused in the second base station coverage area adjacent the
first base station coverage area, the first mode of operation being
one of the direct mode of operation and the infrastructure mode of
operation. In some embodiments the determination module 926 further
includes a module 927 for selecting, as the first mode, a mode of
operation having lower determined system interference cost
estimate.
[0105] In some embodiments the assembly of modules 700 further
includes an optional module 928 for determining a second direct
mode system interference cost estimate, e.g., based on expected
interference caused to both the first base station coverage area
and the coverage area of said base station, e.g., where the second
wireless terminal is located, if the second wireless terminal and
the first wireless terminal communicate using direct mode, an
optional module 930 for determining a second infrastructure mode
system interference cost estimate, e.g., based on expected
interference caused to both the first base station coverage area
and the coverage area of said base station, if the second wireless
terminal and the first wireless terminal communicate using the
infrastructure mode, an optional module 932 for determining a
second mode of operation for communication from the second wireless
terminal to the first wireless terminal as a function of
interference which will be caused in a base station coverage area
other than a base station coverage area in which the second
wireless terminal is located, said second mode of operation being
one of the second direct mode of operation or the second
infrastructure mode of operation. In some embodiments the module
932 includes a module 934 for selecting the mode of operation
having the lower determined system interference cost estimate.
[0106] The assembly of modules 900 further includes a module 936
for communicating to the first wireless terminal the determined
first mode of operation to be used for communication from the first
wireless terminal to the second wireless terminal, and for
optionally communicating the determined second mode of operation
for communication from the second wireless terminal. The module 936
in some embodiments include a module 938 for transmitting the
determined first mode of operation to the first wireless terminal
via the first base station included in the first base station
coverage area. Assembly of modules 900 further includes a module
940 for transmitting to the second wireless terminal, information
indicating the determined first mode of operation, and optionally
communicating the determined second mode of operation for
communication from the second wireless terminal to the first
wireless terminal.
[0107] The modules shown in dashed lines boxes are optional, and
thus one or more of these modules may be present in some
embodiments while not in others. The dashed boxes indicate that
although these modules are included in the assembly of modules 900
in various embodiments, the processor 802 may execute such an
optional module in embodiments where the step to which these
modules correspond, is performed. In some embodiments, one or more
modules shown in FIG. 9 which are included within another module
may be implemented as an independent module or modules. For
example, module 927, in some embodiments, may be implemented as a
standalone module with regard to module 926.
[0108] For the above discussion it should be appreciated that
numerous variations and embodiments are possible.
[0109] The techniques of various embodiments may be implemented
using software, hardware and/or a combination of software and
hardware. Various embodiments are directed to apparatus, e.g.,
control node, mobile nodes such as mobile terminals, base stations,
communications system. Various embodiments are also directed to
methods, e.g., method of controlling and/or operating a control
node, mobile nodes, base stations and/or communications systems.
Various embodiments are also directed to non-transitory machine,
e.g., computer, readable medium, e.g., ROM, RAM, CDs, hard discs,
etc., which include machine readable instructions for controlling a
machine to implement one or more steps of a method.
[0110] It is understood that the specific order or hierarchy of
steps in the processes disclosed is an example of exemplary
approaches. Based upon design preferences, it is understood that
the specific order or hierarchy of steps in the processes may be
rearranged while remaining within the scope of the present
disclosure. The accompanying method claims present elements of the
various steps in a sample order, and are not meant to be limited to
the specific order or hierarchy presented.
[0111] In various embodiments nodes described herein are
implemented using one or more modules to perform the steps
corresponding to one or more methods, for example, signal
processing, message generation and/or transmission steps. Thus, in
some embodiments various features are implemented using modules.
Such modules may be implemented using software, hardware or a
combination of software and hardware. Many of the above described
methods or method steps can be implemented using machine executable
instructions, such as software, included in a machine readable
medium such as a memory device, e.g., RAM, floppy disk, etc. to
control a machine, e.g., general purpose computer with or without
additional hardware, to implement all or portions of the above
described methods, e.g., in one or more nodes. Accordingly, among
other things, various embodiments are directed to a
machine-readable medium including machine executable instructions
for causing a machine, e.g., processor and associated hardware, to
perform one or more of the steps of the above-described method(s).
Some embodiments are directed to a device, e.g., communications
node, including a processor configured to implement one, multiple
or all of the steps of one or more methods of the invention.
[0112] In some embodiments, the processor or processors, e.g.,
CPUs, of one or more devices, e.g., communications nodes such as a
control node, access nodes and/or wireless terminals, are
configured to perform the steps of the methods described as being
performed by the communications nodes. The configuration of the
processor may be achieved by using one or more modules, e.g.,
software modules, to control processor configuration and/or by
including hardware in the processor, e.g., hardware modules, to
perform the recited steps and/or control processor configuration.
Accordingly, some but not all embodiments are directed to a device,
e.g., communications node, with a processor which includes a module
corresponding to each of the steps of the various described methods
performed by the device in which the processor is included. In some
but not all embodiments a device, e.g., communications node,
includes a module corresponding to each of the steps of the various
described methods performed by the device in which the processor is
included. The modules may be implemented using software and/or
hardware.
[0113] Some embodiments are directed to a computer program product
comprising a computer-readable medium comprising code for causing a
computer, or multiple computers, to implement various functions,
steps, acts and/or operations, e.g. one or more steps described
above. Depending on the embodiment, the computer program product
can, and sometimes does, include different code for each step to be
performed. Thus, the computer program product may, and sometimes
does, include code for each individual step of a method, e.g., a
method of controlling a communications device or node. The code may
be in the form of machine, e.g., computer, executable instructions
stored on a computer-readable medium such as a RAM (Random Access
Memory), ROM (Read Only Memory) or other type of storage device. In
addition to being directed to a computer program product, some
embodiments are directed to a processor configured to implement one
or more of the various functions, steps, acts and/or operations of
one or more methods described above. Accordingly, some embodiments
are directed to a processor, e.g., CPU, configured to implement
some or all of the steps of the methods described herein. The
processor may be for use in, e.g., a communications device or other
device described in the present application.
[0114] While described in the context of an OFDM system, at least
some of the methods and apparatus of various embodiments are
applicable to a wide range of communications systems including many
non-OFDM and/or non-cellular systems.
[0115] Numerous additional variations on the methods and apparatus
of the various embodiments described above will be apparent to
those skilled in the art in view of the above description. Such
variations are to be considered within the scope. The methods and
apparatus may be, and in various embodiments are, used with CDMA,
orthogonal frequency division multiplexing (OFDM), and/or various
other types of communications techniques which may be used to
provide wireless communications links between access nodes and
mobile nodes. In some embodiments the access nodes are implemented
as base stations which establish communications links with mobile
nodes using OFDM and/or CDMA. In various embodiments the mobile
nodes are implemented as notebook computers, personal data
assistants (PDAs), or other portable devices including
receiver/transmitter circuits and logic and/or routines, for
implementing the methods.
* * * * *